Device for transmitting measured values to alpha distant point



ES TO A DISTAN'I POINT Aug..l, 1933. H. HAUSRATH DEVICE FOR TRANSMITTING MEASURED VALU Filed Dec. 14, 1929 is possible.

. known arrangements, insofar Patented Aug. 1, 1933 VALUE Herbert Hausrath,

to theFi'rm Neu TES' PATENT OFFICE 1,920,788 DEVICE FOR TRANSMITTING MEASURED Kiel, Germany Application December 14, 1929, Serial No. 414,200,

and in Germany December 20, 1928 It is known to transmit measure '1 Claims.

d values to I points of Considerable distance by means of cur- I rent impulses, whose duration is proportional to the distance of a measuring instrume from its zero point.

nt indicator By these known arrangements a transmission over considerable distances These known arrangements, however, owing to the principle on which they are based have the inherent disadvantage that the I operating elements at the transmitter and at the receiver must be synchronized. Besides, the construction of the receiver is comparatively very expensive.

It is the purpose of 'thepresent invention to produce a transmitting device formentioned purpose inthe abovewhich the aforementioned disadvantages are not present and by which through a comparatively very simple apparatus at the transmitter and at the receiver a transmission of the values maybe effected. This problem is solved, according to invention by using a the present transmitter which varies the time period of two periodically recurrent current impulses in dependency of the value to be transmitted, and by using a receiver of the so-called cross coil type" which measures or indicates the quotient of the energies supplied to the two cross coils, i. e. which time periods of transmitter. Such measures the quotient of the the two current impulses at the an arrangement has the same advantages in result produced as the heretofore of the constancy of the current source as it is independent and insofar "as it permits likewise the transmission over very great distances. that it does not require It has the additional advantage synchronized operatin elements at the transmitter and at the receiver,

since even if the speed the transmitter by which are produced should vary, current impulses in relation to each 0 thesame.v Lastly,v novel arrangement tively arranging manner, because of the driving motor at the current impulses the time periods of the ther remain 'a further advantage of my is the possibility of constructhe receiver in a very simple I can even use an ordinary commercially obtainable cross-coil instrument, provided care is taken that the duration of the oscillations of the movable system in strument is large compared with the the impulses at the pose of slowing down instrument any well such an in-- duration of transmitter. For the purthe oscillations of such an known means may be employed, such as increasing the mass of the oscillating elements or similar means. In the accompanyin increasing the damping or g drawing I that the relation of the time periods the duration of the currents which the flow by S TO A DISTANT POINT Karlsruhe, Germany, assignor feldt & KuhnkeG. m. b. H.,

one of their sides in a diagonal line and at their two other sides in a line in parallel to the axis of rotation as will readily be understood from the drawing. 3 represents a brush sliding on the commutator and capable of being moved over the commutator in the directions of the double arrow b by an indicator hand 3 or any contrivance whose position with respect to a zero point it is desired to transmit. 4 represents a battery or other suitable source of current, 8 represents a cross coil instrument at thereceiving station and 5, 6 and '7 are the connecting line conductors between the transmitter and the receiver. The line conductors 5 and 6 are each connected at the transmitter to one of the commutator segments 1 and 2, and at the receiving station each conductor is connected to one end of the two coils, respectively, the other ends of these coils being connected with each other and being jointly connected to the line conductor 7, leading to current source 4.

From this arrangement it will clearly appear and thus way of the segments 1 and 2 to the two coils at the receiving station will vary in accordance with the position into which brush a has been shifted 9 on the commutator in' axial .lirection. For instance, as shown in Fig. 1 the brush stands about in the middle between the two commutator ends and consequently the two time periods of the current impulses sent through the two coils at the receiver are equal. Since the'cross 'coll instrument will adjust itself in accordance with the quotient of the time period of the two current impulses, its final position will constitute a single valued relation to the position of brush 3 on 106 the commutator.

The transmitting arrangement shown for instance in Fig. 1 requires three conductors between the transmitter and receiver. Fig. 2 shows an I arrangement in which only two line conductors are necessary. In this figure 1 and 2 again indicate the two commutator segments developed into a plane similar to the manner shown in Fig. 1. There are arranged three commutator cylinders C C C Two of them are fixed on the shaft A of a motor M while the third cylinder C is driven from a motor M The commutator cylinders are assumed to rotate in the direction of the arrow a. 3 represents the/brushes which are shifted in the direction of the commutator axis as indicated by double arrow b. The brushes are assumed to be shifted e.g. by the indicator of an instrument whose position it is desired to transmit. 4 represents again the source of current necessary for the transmission and symbolized as in Fig. 1 by a battery. 9 represents a resistance, the purpose of which is to prevent a short circuit of the current source 4 by the brushes 3 when they pass from one commutator segment to the other. 10 and 11 are the two line conductors leading to the receiver 8, and l2 represents a polarized relay arranged at the receiver and capable of alternately throwing a local source of current 13 onto the two cross coils of the receiver 8. As will be seen from the wiring diagram, a current of alternating polarity flows through relay 12 according to whether the one or other of the brushes is in contact with segment 1 or 2 of the cylinders C C C so that armature 12a of relay 12 will alternately connect one or the other coil of cross coil instrument 8 with the local currentsource 13 at the receiver, otherwise the function of the system is exactly like the one shown anddesoribed with reference to Fig. 1, the two cross coils indicating the position of each of the brushes 3 according to the angular position which the two coils assume relatively to each other, as has been explained at the beginning. Now it is not absolutely necessary that a cross coil instrument be used as a receiver in connection with relay 12.

This polarized relay may also operate in known manner any suitable mechanical follow up" device which will indicate the varying positions of a brush 3 owing to the varying durations of the commutator impulses transmitted to relay 12.

This mode of transmission affords also the reception with a single receiving instrument of the average position of a number of "indicators at the transmitter. This average is indicated atthe receiverif the current impulses of the several indicators are successively brought into effect at the receiver. For this purpose the commutators C and C are mechanicallycoupled with each other. The commutator segments 1, 2 are. circumferentially displaced with respect to each other on the cylinders C C by insulating pieces 25 and are connected in parallel with the current source 4 by the brushes a and b. Accordingly the impulses corresponding to the positions of the brushes 3 are successively transmitted through the wires 10, 11 to the receiver 8.

If the individual transmitters are physically too far removed from each otherto permit a mechanical coupling such as is described hereinbefore, the transmitters must be synchronized by other means known in the art. complished for instance in the following manner with reference to Fig. 2. The third transmitter C is assumed to be removed from thetransmitters C and C. M and M are synchronous motors being connectedin parallelwith the network N. The insulating portion 25 of (I is displaced opposite to the dead space of C and C and the brushes a and b of C are connected, as

sent.

This may be ac-" the brushes a and b of C and C in parallel with the battery 4. The transmission of the impulses being determined in their character by the position, in axial direction, of brushes 3 of C C C occurs over the wires 10 and 11, since the conductive segments of the three commutators are set circumferentially with respect to one another to come successively in contact with their respective brush 3, as shown one after the other as before described.

In case an ordinary cross coil instrument of commercial type is used, in which no special arrangements are made for artificially increasing its oscillation period so as to make it long compared with the duration of the impulses transmitted, anarrangement may be used in which the cross coils of such an ordinary instrument are permanently traversed by current so as to permanently keep it under the influence of an electromagnetic field. This becomes possible by condensers 14 and 15 of very large capacity which are connected in parallel respectively to these coils. In addition into each of the connecting leads 16, 17, 18 between the condensers 14, 15 and the current source 13, a resistance 19, 20, 21 respectively is placed, these resistances being so large that even for the current impulse of the longest duration which can be sent with a given commutator the condensers will not be completely charged. For such large resistances the line which is built according to the Ferraris princi- ,ple. I

Practical tests with instruments of the type described hereinbefore have shown that the voltages necessary for transmitting the impulses may be extremely low, because already currents of extremely small intensity will produce single valued indications at the-receiver, provided the receiving instrument is just sufliciently damped that it will still execute very small pendulum movements in accordance with the varying current impulses ents are so well known in the art that they do not require any further illustration I claim:

1. Arrangement for transmitting measured values, comprising a transmitter having means for transmitting two periodically recurrent impulses of a gradually variable ratio of duration, including movable means for varying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a receiver for said current impulses of a type responsive to the quotient of the energies supplied to it by said impulses and line conductors between said transmitter and said receiver for transmitting said impulses.

2. Arrangement for transmitting measured values, comprising a transmitter having means or description.

for transmitting two immediately successive and periodically recurrent impulses of a gradually variable ratio of duration, including movable means for varying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a receiver for said current impulses of a type responsive to the quotient of the energies supplied to it by said impulses and line conductors between said transmitter and said receiver for transmitting said impulses.

3. Arrangement for transmitting measured values, comprising a transmitter having means for transmitting two periodically recurrent impulses of a gradually variable ratio of duration, including movable means for varying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a cross coil instrument connected to said transmitter to receive said impulses in its coils, and indicating by the relative position of its coils the quotient of the energies supplied to its coils, and line conductors between said transmitter and said receiver.

4. Arrangement for transmitting measured values, comprising a transmitter having means for transmitting two immediately successive and periodically recurrent impulses of a gradually variable ratio of duration, including movable means for varying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a cross coil instrument connected to said transmitter to receive said impulses in its coils, and indicating by the relative position of its coils the quotient of the energies supplied to its coils, and line conductors between said transmitter and said receiver.

5. Arrangement for transmitting measured values, comprising a transmitter having means for transmitting two periodically recurrent 'impulses of a gradually variable ratio of duration, including movable means for carrying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a cross coil instrument responsive to current impulses in its coils, and indicating by the relative position of its coils the quotient of the impulse energies supplied to its coils, and line conductors between said transmitter and said receiver for transmitting said periodic impulse to said coils, -:aid cross coil instrument having a condenser in recurrent sequence two periodically recurrent current impulses of a gradually variable ratio of duration, each transmitter including movable means for varying the ratio of duration of its two impulses, each transmitter having an indicator of the values to be transmitted, and means for operating its movable means by said indicator in accordance with such values, and a receiver connected to all of said transmitters and adapted to receive the current impulses from each transmitter in immediately successive recurrent sequence, said receiver being of a type responsive to the quotient of the energies supplied to it by the two impulses from each transmitter, said receiver having sufiicient damping to indicate the average value of the indications transmitted by said transmitters.

7. Arrangement for transmitting measured values, comprising a transmitter having means for transmitting two periodically recurrent impulses of a gradually variable ratio of duration, including movable means for varying such ratio, an indicator of the values to be transmitted and means for operating said movable means by said indicator in accordance with such values, and a polarized relay at the'receiving end of the system for receiving said impulses, and adapted to respond in its action in accordance with the polarity of said impulses, a cross coil instrument at the receiving end, a local current source connected at one pole jointly to one end of each coil, a double contact having each of its contacts connected to one of the free ends of said coils, a contact arm connected to the other pole of said local source and being operated by said relay to energize one or the other coil of said instrument in accordance with the polarity and duration of the impulses received, said cross coil instrument indicating by the relative position of its coils the quotient of the energies supplied to its coils by said local source in accordance with the quotient of the energies of the impulses supplied by the transmitter to said relay.

'HERBERT HAUSRATH. 

